Control system



- PATENTED'OOT. 15, 1907. .1 s. MAINN. CONTROL SYSTEM. APPLIOLTIOH FILED 1080.18, 1905.

mr/vsss/s 4 J/Vl IE/VTOH flrthuriMann, By

25 l in any event on very light loads. If, on the other hand,

a pump capo-bled disposing of the average accumula;

'ARTHUR s. MANN,

OF SGHENECTADY, NEW YORK, ASSIGNOB TO GENERAL ELECTRIC COMPANY; ACORPORATION OF NEW YORK.

con'rnon sjsrsrnm.

' No. sconce.

Specification of Letters Patent. I .dppllcation iilscl December is; 1905. Serial No. 292,130.

Patented Oct. 15,1907.

To all whom it only meant;

..Bo it known that I, Airmen S.MnnN,a, citizen of the United Statenresiding at Schenectady, county of Schenecl'BAlY, State of New York, have invented cer-' tain new anrluseful Improvements in Control Systeins, of which the following is a. specification.

The object oithe present invention is to produce a sirnple and eflicient system oicontrol for automatically governing apparatus which is called upon to perform worli'intermittently and in varying amounts. An errumple of this character of apparatus is to be found in steem'heatingsystenrs wherein the condensed steain' which collects in the various pipes throughout the system is returned to the boilers by means of power driven pump. If. it is desired to maintain the pipesfeirly clear'oiwnter it is necessary that the pump shall be at alltimes reedy to operate in order to carry ewuy hnysccuniulotion of water. It is evident that under the varying conditions of temperature and service oi an extended heating systern the rate at which the water collects in the pipes is an extreniely variable uantity, and if s pumpof sufiicient cupacity to take care of-the maximum accumuliition isoperot'ed con tinuously, then, when the rate of accumulation is small, tho pump must necessarilyat tignes run substantially on no load, end,

1 tion of water is employed, then at times it will be in- I Isufli'cient to keep the pipes clear.

In order tluit a pump sofiieiently large to take core of a maximum occur-mile,-

ftion of water may be employed without-being required to run on extremely light loads, Ihnvedevised means whereby the pump 'is operated intermittently, the

starting of the purnp being automatic and being effected .at any desired predetermined intervals of .time, together with means controlled by the discharge of .the pump for again stopping the pump when there is but little water passing through the pump. I prefer to employ an electric motor for operating the pump and to control the starting and stopping of the pump by starting and stopping the motor. I v

Thus it will be seen that in one. of its aspects the present invention may be considered as relatirig to means 4 for starting :3. motor at predetermined intervals of time and automnticnliy stoppingthe motor if and whenever the motor lced falls below a predetermined value.

In another aspect the present invention may be com I sidered as comprising 5. power driven pump, together with. controlling-apparatus for startip the pump at predetermined intervals of time and de rrnining the duration of operation of thepump by the-mite of discharge. flhe present invention, in the above and other of its espects, will-he inors fully understood and further ob- 'iects thereof will appear from the following description.

Q; 111 the accompanying drawing I have illustrated diainterval may be varied to suit the grammatically one form of the present invention, and

" similar reference characters appearing on said drawing and in. the following description denote like parts.

lteierring to the drawing, 1 indicates a purnp driven by a uiotor having an armature 2 and a field winding 3; 4 is the suction pipe; 5 the discharge pipe; 6 is a starting switch of any usual or desired 'type arranged to connect the motor ton source of current supply i.n-' dicated hy'linc's '1 and 8 and to vary the resistrmce of the motor circuit in starting in the usual manner. The rheostat is illustrated as consisting of a spring ac-. tuated him 9 arranged to'sweep over contacts 10 connocted at'various points along resistance 11, together with an elcctromsgnet 12 aldupted to maintain the arm 9'in its full onf position after the arm has been brought to that position. The present invention contemplates means for entomaticelly operating the rheostat at predetermined in operation at the some intervals. It is of course evident that the means ior so operating the rheostnt may. be varied, since the present invention is not limited to any particular apparatus for accomplishing .this end. The arrangement illustrated for this purpose consists oi clover 13 pivoted at 14 upon'a fixed-support and carrying at one end u weight 15 and at the other "intervals of time, thereby causing the motor to be set end nreceptaclc 16. An arm 17 is connected to the lever 13 at a. point intermediate the pivotal support oi the lever and the weight 15, and at its lower end this sum is provided with a slot 18 into which projects a."

pin 19 extending from the nrrn 9. .lhe length of the slot 18 is sudi that when the' parts nre in the-positig n shown the arm 9 is-free to be moved between its e:- treine limits. Extending through the botwm-ci the. receptacle 16 is a pipe 20 suitably supported on a. bracket 21. The receptacle is preierubly. provided with an elongated flange or gland 2 2 so os tonmke a water-tight joint between the pipe and the redeptacle while at the sometime permitting relative axial move ments between the two. Arrnngcd'ubove the receptacle is a cook 23 receiving water or other liquid fromany suitablesource'. By opening this cock, liquid,"

flows into the receptacle and, by varying the extent of interval elopsing'botween successive cldsingspi the starting rheostat is determined by the rate at which the liquid fiows fiorn the cock 23 and therefore this requirements 01 the existing conditions.

Assuming thnt the ports are in tlid position. shown,

the water or other fluid will flow into the 'receptncle 16 until the receptacle and contained fluid ovorbslances. the weight 15, whereupon the receptacle descends and the member 17 moves the rheos't'at arm into itsothercxtreine position. In descending, the recep- .the discharge pipe of tacle uncovers .Lll opening 24 in the pipe 20 and the fluid discharged through this opening until the partially emptied receptacle is overlmlanced by the weight l5 and the receptacle rises again to the position shown. It in the meantime the electronntgnet l2 lms bet-onuenergized. the rheostat. arm will be held in its runnint, position, but. it not. then the rheostal opens concurrently with the ascent of the receptacle. 'lhus the motor is setv in operation at regular intervals through to action ol the time operating mechanism: so that after the pnup has been brought to rest. in the manner to be hereinafter described it need not necessarily remain idle longer than the period clapsing before the next operation of the rheostat. The duration of operation of theanotor is made to depend upon the amount. of work to be done, and to this end I have provided means depending upon the rate of discharge of the. pump for controlling the maintaining magnet of the rhcostat, so that after the rheostat has been set: and the motor started, the motor will innnedlately come to rest. upon the ascent; of the receptacle, unless there is sullicient water to be pumped to warrant the continued opta'ation of the pump. It is of course trident; that the actual construction and arrangement of parts for carrying out this feature of the present invention may be greatly varied, although the arrangement illustrated provides a simple and effective means for accomplishing the desired result. In the discharge pipe 5 I have arranged a pivoted check valve 25 which, when the pump is operating, swings about its axis to an extent depending upon the rate of discharge of the pump. It Will of course be understood that instead of a pivoted check valve a different form of valve or other device subjected to the discharge current: may be employed. (onnectcd to the valve so as to oscillate in unison therewith is an arm 26 which is in turn connected by means of link 27 to the movable member of a. switch 28. The switch 28, when closed, short: circuits the e'lectromagnet l2, and the arrangement is such that when there no Ilow, or only a small flow in the pump, the switch 28 is closed; but when a predetermined amount of water is being pumped the check valve is opened to such an angle that: the switch 28 is made to open, thereby interrupting thoshort circuit; about the magnet 12 and permittiug it to be energized.

The operation of the apparatus described is as f l- 'lows: Assuming that the receptacle I6 has descended, causing the rheostat to be operated, the motor will start; up in the usual manner and operate the pinup; the rheostat will be held in its operative position momentarily while the receptacle is being emptied; and therefore, iithere is sullicient water in the pipe 4 to make it desirable to continue the operation of the pump, ample time is given for the formation of a. discharge stream past the check'valve and therefore the check valve will be swung about; its axis and the switch 28- opencd. The opening of the switch 28 allows the t-lect.romagnet l2 to be-ome energized so that. when the receptacle again ascends the rheostat arm is held in its operative position by the maintaining magnet. 'lhe pump now continues 'to opt-rate until the discharge stream becomes so small that. the check valve closes sulliciently to close the switch 28:

'lltt't't'tlltlg her following the dcencrgization magnet, the rl'lcostat arm is brought into its operative,

position and the pump caused to operate [or a short period. .llowevcr, alter each operation the switch arm is moved to its open position upon its release by l the actuating member, until such a time when the I discharge stream produced during one of the momen- J tary operations of the pump becomes sutlicicntly I great to cause the switch 28 to open: whereupon the 'rheostat arm will-be held in the (lost-(l position by l the maintaining magnet until the load on the pump 1 drops below the point at which it is desirable to maintain the pump in operation. I Although I have illustrated and described the present'inveution as embodied in. one form only, I do not form shown or to indicated in desire to be limited to the specific any specilic form except as specifically the apptmded claims.

What I claim as new and desire to secure by Let tors Patent 01' the ['nited States, is,'

it. In combination. a motor, a normally rheosiat lhercfor. means for operating said rheostat at predetermined intervals to close the motor circuit and vary the resistance in said clrcuit. and means controlled by the load on the motor for malntninlm; said rheostat in its operated position.

4. In combination. a lnotor. a source of current supply. a switch for completing a circuit. from snld source ofcurrent supply through said motor. means for automatically operating suld switch and holding it momentarily in it's operated position at -predeterminml intervals of tlme to complete the motor circuit. and means controlled h the load on the motor for mainlninitu: said swlteh in its up ernted position.

5. In combination. a motor. a source of current supply. a switch for completimi, a circuit from said source of supply through said motor. means for automatically operating salt] swltchnnd holt'lim. it momentarily In its operated position at predclermlned intervals to complete' tlie meter circuit. and means for malntatnlng said swltch in its operated posltion when the load on the motorexceeds a predetcrmiued value.

ti. In comhllmtion. a motor. :Lsourcc of current supply. a normally open starting rhcostnt for completlng a circuit through said motor from sald source of supply and varying the reslstauce in the motor circuit, means for automntlo nll operating said rheostat and holding it molncnhirlly In its operated position at prctlctermlned inter its. means for maintaining salt! rheostat in its operated position. and means controlled by the load on the motor for renderlng the atoresald means lnuperutlve to maintain the rhedstht in its operallre posltlon when the load on the motor is less termiucd intervals. and means controlled by the load on the motor for maintaining the rheostat in its operated position. I

open starting 

